Even moderate alcohol consumption could spell trouble for AFib patients

A high-density electroanatomic mapping study of 75 patients with atrial fibrillation (AF) has concluded that even a regular alcohol intake—up to 14 standard drinks per week—is associated with impairments in electrical signaling and more electrical evidence of scarring, signaling worse outcomes.

“Excessive alcohol consumption has emerged as a potentially modifiable risk factor for AF,” Aleksandr Voskoboinik, MBBS, and coauthors wrote in Heart Rhythm Jan. 10. “Both binge drinking and habitual alcohol consumption have been implicated in electrical and structural changes involving the left atrium.”

Over-the-top alcohol intake can result in the shortening of atrial refractoriness and slowing of intra-atrial conduction, Voskoboinik and colleagues said, and binge drinking has also been linked to contractile dysfunction related to oxidative stress, mitochondrial damage and cardiac steatosis. And while there’s an established connection between regular alcohol intake and AF, there’s a paucity of electrophysiological data on the subject.

Voskoboinik et al. enrolled 75 patients with AF before ablation, 25 of whom were lifelong nondrinkers, 25 of whom were mild drinkers and 25 of whom were moderate drinkers. A participant was considered a moderate drinker if they consumed anywhere between eight and 21 drinks a week, while mild drinkers consumed between two and seven drinks per week.

The authors performed high-density electroanatomic mapping on all patients with the purpose of determining the impact different degrees of alcohol consumption have on atrial remodeling. They found moderate drinkers had:

  • Significantly lower global bipolar voltages than nondrinkers (1.53 mV compared to 1.89 mV)
  • Slower global conduction velocity than nondrinkers (33.5 cm/s compared to 41.7 cm/s)
  • A higher proportion of complex atrial potentials (7.8 percent compared to 4.5 percent)

Voskoboinik and colleagues said global voltage and conduction velocity didn’t differ significantly between moderate and mild drinkers, but there was a significant increase in global complex potentials and regional low-voltage zones in the septum and lateral wall in mild drinkers compared with nondrinkers.

“Regular moderate alcohol consumption, but not mild consumption, is associated with lower atrial voltage and conduction slowing,” the authors wrote. “These electrical and structural changes may in part explain the propensity to AF in regular drinkers and may represent an important modifiable risk factor for AF."